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作者等用Elias沉淀点法求得聚二甲基硅氧烷-乙苯-邻苯二甲酸二乙酯体系在10—100℃间的一系列θ-溶剂组成。从聚二甲基硅氧烷一个级份(M_η=1.4·10~6)的这些θ-溶液特性粘数测定得到dln[η]θ/dlnT=0.45,按Flory-Fox特性粘数理论计算得dlnh~2_0/dlnF=0.30,即聚二甲基硅氧烷分子的无扰尺寸随温度升高而增大。由于Me_2SiO单元间的偶极-偶极相互作用使分子链的左右式构象的位能低于反式构象的位能。
The authors used the Elias precipitation point method to obtain a series of θ-solvent compositions of a polydimethylsiloxane-ethylbenzene-diethyl phthalate system at 10-100 ° C. From these θ-solution intrinsic viscosities of polydimethylsiloxane in one fraction (M_η = 1.4 · 10 -6), dln [η] θ / dlnT = 0.45 was calculated as Flory-Fox intrinsic viscosity theory dlnh ~ 2_0 / dlnF = 0.30, that is, the size of the polydimethylsiloxane molecule increases with the increase of temperature. Due to the dipole-dipole interaction between the Me_2SiO units, the potential energy of the left-right conformation of the molecular chain is lower than that of the trans conformation.